The stereochemistry of hydrogen abstraction during the hydroxylation of camphor by cytochrome P-450 will be investigated through the use of specifically deuterated camphors. Analysis of the products of oxidation of the 5-exo- and 5-endo-d derivatives of camphor will reveal whether hydroxylation occurs with retention or inversion at the active site, and will, in turn, provide information on the geometry of the enzyme substrate complex. Additionally, the 3-exo- and 3-endo-d derivatives of camphor will be used to determine whether substrate binding occurs through an enolate linkage, in which case the label will be lost from the substrate.